Methods and apparatus for providing a demapping system with phase compensation to demap uplink transmissions

ABSTRACT

Methods and apparatus for providing a demapping system with phase compensation to demap uplink transmissions. In an embodiment, a method is provided that includes detecting a processing type associated with a received uplink transmission, and when the detected processing type is a first processing type then performing the following operations: removing resource elements containing reference signals from the uplink transmission; layer demapping remaining resource elements of the uplink transmission into two or more layers; phase compensating all layers to generate phase compensated layers; and soft-demapping all phase compensated layers to produce phase compensated soft-demapped bits.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part (CIP) of U.S. patentapplication Ser. No. 16/404,029 filed on May 6, 2019 and entitled“METHOD AND APPARATUS FOR PROVIDING A DEMAPPING SYSTEM TO DEMAP UPLINKTRANSMISSIONS.”

The application Ser. No. 16/404,029 claims priority from U.S.Provisional Application No.: 62/667,215 filed on May 4, 2018 andentitled “METHOD AND APPARATUS FOR PROVIDING A SAMPLE SINGLE-SHOTPROCESSING SCHEME FOR DATA TRANSMISSION.” The U.S. ProvisionalApplication No.: 62/667,215 filed on May 4, 2018 was incorporated byreference into the application Ser. No. 16/404,029 in its entirety.

This application claims priority from U.S. Provisional Application No.:62/978,700 filed on February 19, 2020 and entitled METHOD AND APPARATUSFOR PROVIDING A SAMPLE SINGLE-SHOT PROCESSING SCHEME FOR DATATRANSMISSION, which is incorporated by reference herein in its entirety.

FIELD

The exemplary embodiments of the present invention relates totelecommunications network. More specifically, the exemplary embodimentsof the present invention relate to receiving and processing data streamsusing a wireless communication network.

BACKGROUND

With a rapidly growing trend of mobile and remote data access over ahigh-speed communication network such as Long Term Evolution (LTE),fourth generation (4G), fifth generation (5G) cellular services,accurately delivering and deciphering data streams become increasinglychallenging and difficult. The high-speed communication network which iscapable of delivering information includes, but not limited to, wirelessnetwork, cellular network, wireless personal area network (“WPAN”),wireless local area network (“WLAN”), wireless metropolitan area network(“MAN”), or the like. While WPAN can be Bluetooth or ZigBee, WLAN may bea Wi-Fi network in accordance with IEEE 802.11 WLAN standards.

In 5G systems, reference signals may be included in uplinktransmissions. These signals are used to estimate channel conditions orfor other purposes. However, these signals are mixed in with data sothat the reference signals must be accounted for when the data isprocessed. For example, when processing data received in resourceelements, special processing may be needed to skip over resourceelements that contain the reference signals. Even if the referencesignals are set to zero or empty, their resource elements still need tobe accounted for when processing the data.

Therefore, it is desirable to have a system that can efficiently demapreceived uplink transmissions while overcoming the disadvantages ofconventional systems.

SUMMARY

In various exemplary embodiments, methods and apparatus are provided fora demapping system that efficiently demaps 4G and 5G uplinktransmissions. When a first type of processing is used, referencesignals are removed from the received resource elements in an uplinktransmission before layer demapping. After layer demapping, softdemapping is then performed prior to descrambling. When a second type ofprocessing is used, the received resource elements are despread beforethe soft demapping process. In this second case, reference signalremoval and layer demapping is bypassed. When a third type of processingis used, the received resource elements are input directly to the softmapper and bypass the despreader. Thus, the demapping system operates toprovide fast and resource efficient demapping of received uplinktransmissions in 4G and 5G wireless networks.

In an embodiment, a method is provided that includes detecting aprocessing type associated with a received uplink transmission, and whenthe detected processing type is a first processing type then performingthe following operations: removing resource elements containingreference signals from the uplink transmission; layer demappingremaining resource elements of the uplink transmission into two or morelayers; soft-demapping the two or more layers to produce soft-demappeddata. The method also comprises descrambling the soft-demapped data toproduce descrambled data, and processing the descrambled data togenerate uplink control information (UCI).

In an embodiment, an apparatus is provided that includes a detector thatdetects a processing type associated with a received uplinktransmission, and a reference signal (RS) remover that removes resourceelements containing reference signals from the uplink transmission, whenthe detected processing type is a first processing type. The apparatusalso includes a layer demapper that demaps remaining resource elementsof the uplink transmission into two or more layers, when the detectedprocessing type is the first processing type, and a soft demapper thatsoft-demaps the two or more layers to produce soft-demapped bits, whenthe detected processing type is the first processing type.

In an embodiment, a method is provided that includes detecting aprocessing type associated with a received uplink transmission, and whenthe detected processing type is a first processing type then performingthe following operations: removing resource elements containingreference signals from the uplink transmission; layer demappingremaining resource elements of the uplink transmission into two or morelayers; phase compensating all layers to generate phase compensatedlayers; and soft-demapping all phase compensated layers to produce phasecompensated soft-demapped bits.

In an embodiment, an apparatus is provided that comprises a detectorthat detects a processing type associated with a received uplinktransmission, and a layer demapper that demaps resource elements of theuplink transmission into two or more layers, when the detectedprocessing type is the first processing type. The apparatus alsocomprises a phase compensation circuit that phase compensates alllayers, and a soft demapper that soft-demaps two or more phasecompensated layers to produce phase compensated soft-demapped bits, whenthe detected processing type is the first processing type.

Additional features and benefits of the exemplary embodiments of thepresent invention will become apparent from the detailed description,figures and claims set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

The exemplary aspects of the present invention will be understood morefully from the detailed description given below and from theaccompanying drawings of various embodiments of the invention, which,however, should not be taken to limit the invention to the specificembodiments, but are for explanation and understanding only.

FIG. 1 shows a block diagram of a communication network in which uplinktransmissions from user equipment are demapped by exemplary embodimentsof a demapping system.

FIG. 2 shows an exemplary embodiment of a demapping system.

FIG. 3 shows an exemplary embodiment of a layer demapper for use in thedemapping system shown in FIG. 2.

FIG. 4 shows an exemplary method for performing demapping in accordancewith exemplary embodiments of a demapping system.

FIG. 5 shows an exemplary embodiment of a phase compensator for use inthe soft demapper provided in the demapping system shown in FIG. 2.

FIG. 6 shows an exemplary embodiment of the soft demapper provided inthe demapping system shown in FIG. 2.

FIG. 7 shows an exemplary method for performing FQ phase compensationsfor use with the soft demapper provided in the demapping system shown inFIG. 2.

FIG. 8 is a block diagram illustrating a processing system having anexemplary embodiment of a demapping system.

DETAILED DESCRIPTION

Aspects of the present invention are described herein the context ofmethods and apparatus for demapping data received in 5G uplinktransmission.

The purpose of the following detailed description is to provide anunderstanding of one or more embodiments of the present invention. Thoseof ordinary skills in the art will realize that the following detaileddescription is illustrative only and is not intended to be in any waylimiting. Other embodiments will readily suggest themselves to suchskilled persons having the benefit of this disclosure and/ordescription.

In the interest of clarity, not all of the routine features of theimplementations described herein are shown and described. It should beunderstood that in the development of any such actual implementation,numerous implementation-specific decisions may be made in order toachieve the developer's specific goals, such as compliance withapplication- and business-related constraints, and that these specificgoals will vary from one implementation to another and from onedeveloper to another. Moreover, it will be understood that such adevelopment effort might be complex and time-consuming, but wouldnevertheless be a routine undertaking of engineering for those ofordinary skills in the art having the benefit of embodiments of thisdisclosure.

Various embodiments of the present invention illustrated in the drawingsmay not be drawn to scale. Rather, the dimensions of the variousfeatures may be expanded or reduced for clarity. In addition, some ofthe drawings may be simplified for clarity. Thus, the drawings may notdepict all of the components of a given apparatus (e.g., device) ormethod. The same reference indicators will be used throughout thedrawings and the following detailed description to refer to the same orlike parts.

The term “system” or “device” is used generically herein to describe anynumber of components, elements, sub-systems, devices, packet switchelements, packet switches, access switches, routers, networks, modems,base stations, eNB (eNodeB), computer and/or communication devices ormechanisms, or combinations of components thereof. The term “computer”includes a processor, memory, and buses capable of executing instructionwherein the computer refers to one or a cluster of computers, personalcomputers, workstations, mainframes, or combinations of computersthereof.

IP communication network, IP network, or communication network means anytype of network having an access network that is able to transmit datain a form of packets or cells, such as ATM (Asynchronous Transfer Mode)type, on a transport medium, for example, the TCP/IP or UDP/IP type. ATMcells are the result of decomposition (or segmentation) of packets ofdata, IP type, and those packets (here IP packets) comprise an IPheader, a header specific to the transport medium (for example UDP orTCP) and payload data. The IP network may also include a satellitenetwork, a DVB-RCS (Digital Video Broadcasting-Return Channel System)network, providing Internet access via satellite, or an SDMB (SatelliteDigital Multimedia Broadcast) network, a terrestrial network, a cable(xDSL) network or a mobile or cellular network (GPRS/EDGE, or UMTS(where applicable of the MBMS (Multimedia Broadcast/Multicast Services)type, or the evolution of the UMTS known as LTE (Long Term Evolution),or DVB-H (Digital Video Broadcasting-Handhelds)), or a hybrid (satelliteand terrestrial) network.

FIG. 1 shows a block diagram of a communication network 100 in whichplink transmissions from user equipment are demapped by exemplaryembodiments of a demapping system (DS) 152. The network 100 includespacket data network gateway (“P-GW”) 120, two serving gateways (“S-GWs”)121-122, two base stations (or cell sites) 102-104, server 124, andInternet 150. P-GW 120 includes various components 140, such as billingmodule 142, subscribing module 144, and/or tracking module 146 tofacilitate routing activities between sources and destinations. Itshould be noted that the underlying concept of the exemplary embodimentsof the present invention would not change if one or more blocks (ordevices) were added to or removed from diagram 100.

The network configuration 100 may also be referred to as a fourthgeneration (“4G”), Long Term Evolution (LTE), Fifth Generation (5G), NewRadio (NR) or combination of 4G and 5G cellular network configurations.Mobility Management Entity (MME) 126, in one aspect, is coupled to basestations (or cell site) and S-GWs capable of facilitating data transferbetween 4G LTE and 5G. MME 126 performs various controlling/managingfunctions, network securities, and resource allocations.

The S-GW 121 or 122, in one example, coupled to P-GW 120, MME 126, andbase stations 102 or 104, is capable of routing data packets from basestation 102, or eNodeB, to P-GW 120 and/or MME 126. A function of S-GW121 or 122 is to perform an anchoring function for mobility between 3Gand 4G equipments. S-GW 122 is also able to perform various networkmanagement functions, such as terminating paths, paging idle UEs,storing data, routing information, generating replica, and the like.

The P-GW 120, coupled to S-GWs 121-122 and Internet 150, is able toprovide network communication between user equipment (“UE”) and IP basednetworks such as Internet 150. P-GW 120 is used for connectivity, packetfiltering, inspection, data usage, billing, or PCRF (policy and chargingrules function) enforcement, et cetera. P-GW 120 also provides ananchoring function for mobility between 4G and 5G packet core networks.

Base station 102 or 104, also known as cell site, node B, or eNodeB,includes one or more radio towers 110 or 112. Radio tower 110 or 112 isfurther coupled to various UEs, such as a cellular phone 106, a handhelddevice 108, tablets and/or iPad® 107 via wireless communications orchannels 137-139. Devices 106-108 can be portable devices or mobiledevices, such as iPhone BlackBerry®, Android®, and so on. Base station102 facilitates network communication between mobile devices such as UEs106-107 with S-GW 121 via radio towers 110. It should be noted that basestation or cell site could include additional radio towers as well asother land switching circuitry.

To improve efficiency and/or speed-up extracting uplink controlinformation received from any of the user equipment, a demapping system152 is provided that operates according to one of three processingtypes. In an embodiment, demapping system 152 applies phase compensationto the received bits as a first stage of the demapping process. When afirst type of processing is used, reference signals are removed from thereceived resource elements of an uplink transmission before layerdemapping. After layer demapping is completed, soft demapping is thenperformed prior to descrambling. When a second type of processing isused, the received resource elements are despread before the softdemapping process. In this second case, reference signal removal andlayer demapping is bypassed. In a third processing type, the receivedresource elements bypass RE removal, layer demapping and despreading andare input directly to a soft demapper. A more detailed description ofthe demapping system 152 is provided below.

FIG. 2 shows an exemplary detailed embodiment of the demapping system152 shown in FIG. 1. FIG. 2 shows user equipment (“UE”) 224 havingantenna 228 that allows wireless communication with base station 112through wireless transmissions 226. The UE 224 transmits uplinkcommunications 230 that are received by base station front end (FE) 228that outputs received symbols 234 that include received referencesymbols. In an embodiment, the base station includes gain normalizer202, inverse transform block (IDFT) 204, configuration parameters 222,the demapping system 152, descrambler 218, and combiner/extractor 220.In an exemplary embodiment, the demapping system 152 includes processingdetector 208, RS (reference signal or symbol) remover 210, layerdemapper 212, despreader 214, and soft demapper 216. In an embodiment,the soft demapper 216 includes a phase compensation circuit 232 thatapplies phase compensation to the input FQ bits as a first stage of thesoft demapping process. The output of the soft demapper 216 is input tothe descrambler 218 and its output is input to the combiner/extractor220 that produces decoded UCI information.

In an embodiment, the demapping system 154 processes 1 symbol at a time,which may come from multiple layers for NR, and the demapping system 154processes the whole subframe or slot of a layer for LTE covering lmstransmission time interval (TTI), 7-OFDM symbol (OS) short (s) TTI, and⅔-OS sTTI. The modulation order can be derived as follows.

-   1. (π/2) BPSK for NR-   2. (π/2) BPSK for LTE sub-PRB, QPSK, 16QAM, 64QAM, and 256QAM

Furthermore, demapping rules apply to constellations as defined in LTE(4G) and/or NR (5G) standards.

Configuration Parameters (Block 222)

In an embodiment, the configuration parameters 222 comprise multiplefields that contain parameters for use by multiple blocks shown in FIG.2. For example, some of the configuration parameters 222 control theoperation of the gain normalizer 202, IDFT 204 and demapping system 152.In an embodiment, the configuration parameters 222 may indicate that thegain normalizer 202 and the IDFT 204 are to be bypassed.

Gain Normalizer (Block 202)

In an embodiment, the gain normalizer 202 performs a gain normalizationfunction on the received uplink transmission. For example, the gainnormalizer 202 is applicable to LTE and NR DFT-s-OFDM cases. Inputsamples will be normalized as follows per data symbol per subcarrierwith a norm gain value calculated per symbol as follows.

Gainnorm_out [Ds][sc]=(Gainnorm_in [Ds][sc])/(Norm_Gain[Ds])

IDFT (Block 204)

The IDFT 204 operates to provide an inverse transform to generate timedomain signals. In an embodiment, the IDFT 204 is enabled only for LTEand NR DFT-s-OFDM and LTE sub-PRB. In an embodiment, the inputs andoutputs are assumed to be 16 bits I and Q values, respectively. The DFTand IDFT operations are defined as follows.

${{DFT}\text{:}{X\lbrack k\rbrack}} = {\frac{1}{\sqrt{N}}{\sum\limits_{n = 0}^{N - 1}\; {{ϰ\lbrack n\rbrack}W_{N}^{kn}}}}$and${{IDFT}\text{:}{X\lbrack k\rbrack}} = {\frac{1}{\sqrt{N}}{\sum\limits_{n = 0}^{N - 1}\; {{ϰ\lbrack n\rbrack}W_{N}^{- {kn}}}}}$where W_(N)=e^(−2πj/N).

Processing Type Detector (Block 208)

In exemplary embodiments, the processing type detector 214 detects thetype of processing to be performed by the system. For example, thisinformation may be detected from the configuration parameters 222. In anembodiment, the processing type detector 208 operates to detect one ofthree processing types, which cover the operation of the system asfollows.

-   1. Type 1—5G NR DFT-s-OFDM-   2. Type 1—5G NR CP-OFDM-   3. Type 2—5G NR PUCCH Format 4-   4. Type 3—4G LTE DFT-s-OFDM-   5. Type 3—4G LTE sub-PRB allocation

RS Remover (Block 210)

In an embodiment, the RS remover 210 operates during Type 1 processingto remove RS resource elements from the received data stream to producea stream of data that is input to the layer demapper. For example, theRE locations of the RS symbols are identified and the data is re-writteninto one or more buffers to remove the RS symbols to produce an outputthat contains only data. In an embodiment, Type 1 processing includesRS/DTX removal, layer demapping with an interleaving structure, softdemapping, and descrambling. A benefit of removal of RS before layeringis to operate a single shot descrambling without any disturbance in acontinuous fashion with no extra buffering.

Layer Demapper (Block 212)

FIG. 3 shows an exemplary embodiment of layer demapper 212. In anembodiment, Data and signal to interference noise ratio (SINR) comingfrom multiple layers Data(L0-L3) and SINR(L0-L3) of a certain subcarrierwill be transferred into a layer demapping circuit 302 viamulti-threaded read DMA operation. In this case, each thread will pointto the memory location of different layers for a certain symbol as shownin FIG. 3. The layer demapping circuit 302 produces demapped data andmultiple pSINR reports per layer. In an embodiment, for NR theDMRS/PTRS/DTX REs will be removed from the information stream prior tosoft demapper both from I/Q and SINR samples.

Referring again to FIG. 2, additional blocks of the demapping system 152are described in detail below.

Despreader (Block 214)

In an embodiment, the despreader 214 provides despreading for PUCCHFormat 4 only. It consists of combining the repeated symbols along thefrequency axis upon multiplying them with the conjugate of the properspreading sequence. The spreading sequence index as well as thespreading type for combining the information in a correct way will begiven by the configuration parameters 222. This process is alwaysperformed over 12 REs in total. The number of REs that will be pushedinto subsequent blocks will be reduced by half or ¼th after despreadingdepending upon the spreading type. Combined results will be averaged andstored as 16-bit before soft demapping.

Soft Demapper (Block 216)

In an embodiment, the soft demapper 216 includes the phase compensationcircuit 232 that acts as a first stage to perform phase compensation ofthe received FQ signals before soft demapping. A more detaileddescription of the phase compensation circuit 232 is provided below. Thesoft demapping principle is based on computing the log-likelihood ratio(LLR) of a bit that quantifies the level of certainty on whether it islogical zero or one. Under the assumption of Gaussian noise, LLR for thei-th bit is given by:

${LLR_{i}} = {{\ln \left( \frac{P\left( {{bit}_{i} = {0/r}} \right)}{P\left( {{bit}_{i} = {1/r}} \right.} \right)} = {{\ln \left( \frac{\sum_{j}e^{\frac{- {({ϰ - c_{j}})}^{2}}{2\sigma^{2}}}}{\sum_{k}e^{\frac{- {({ϰ - c_{k}})}^{2}}{2\sigma^{2}}}} \right)} = {{\ln \left( {\sum\limits_{j}e^{\frac{- {({ϰ - c_{j}})}^{2}}{2\sigma^{2}}}} \right)} - {\ln \left( {\sum\limits_{k}e^{\frac{- {({ϰ - c_{k}})}^{2}}{2\sigma^{2}}}} \right)}}}}$

where c_(j) and c_(k) are the constellation points for which i-th bittakes the value of 0 and 1, respectively. Note that for the gray mappedmodulation schemes given in [R1], x may be taken to refer to a singledimension I or Q. Computation complexity increases linearly with themodulation order. A max-log MAP approximation has been adopted in orderto reduce the computational complexity. Note that this approximation isnot necessary for QPSK since its LLR has only one term on both numeratorand denominator.

${{\ln {\sum\limits_{m}e^{- d_{m}}}} \cong {\max \left( {- d_{m}} \right)}} = {\min \left( d_{m} \right)}$

This approximation is accurate enough especially in the high SNR regionand simplifies the LLR calculation drastically avoiding the complexexponential and logarithmic operations. Given that I and Q are real andimaginary part of input samples, the soft LLR is defined as follows for(it/2) BPSK, QPSK, 16QAM, 64QAM, and 256QAM, respectively.

It should be noted that (it/2) BPSK is only applicable to NR DFT-s-OFDMand LTE sub-PRB cases. There are two flavors of this modulation format.For the first case, the constellation is shifted by (it/2) acrosssubcarriers along the frequency axis. Hence, the demapper will changethe demapping rule from subcarrier to subcarrier with the orderspecified below. For the other scenario, the demapping rule will staythe same along the frequency axis and soft demapper will always generateLLRs using the first rule specified below. This behavior of changing theLLR generation rule across frequencies or not will be controlled by aconfiguration parameter.

In an embodiment, the soft demapper 216 includes a first minimumfunction component (“MFC”), a second MFC, a special treatment component(“STC”), a subtractor, and/or an LLR generator. A function of softdemapper 216 is to demap or ascertain soft bit information associated toreceived symbols or bit streams. For example, soft demapper 216 employssoft demapping principle which is based on computing the log-likelihoodratio (LLR) of a bit that quantifies the level of certainty as towhether it is a logical zero or one. To reduce noise and interference,soft demapper 216 is also capable of discarding one or more unusedconstellation points relating to the frequency of the bit stream fromthe constellation map.

The STC, in one aspect, is configured to force an infinity value as oneinput to the first MFC when the stream of bits is identified and aspecial treatment is needed. For example, a predefined control signalwith a specific set of encoding categories such as ACK with a set ofpredefined encoding categories requires a special treatment. One of thespecial treatments, in one aspect, is to force infinity values as inputsto MFCs. For example, STC force infinity values as inputs to the firstand the second MFCs when the stream of bits is identified as ACK or RIwith a predefined encoding category. The STC, in one instance, isconfigured to determine whether a special treatment (or specialtreatment function) is required based on received bit stream or symbols.In one aspect, the 1-bit and 2-bit control signals with predefinedencoding categories listed in Table 1 require special treatments. Itshould be noted that Table 1 is exemplary and that other configurationsare possible.

TABLE 1 No. Control Signal with Encoding Categories Renamed Categories 1O^(ACK) = 1 ACK[1] 2 O^(ACK) = 1 ACK bundling ACK[2] 3 O^(ACK) = 2ACK[3] 4 O^(ACK) = 2 ACK bundling ACK[4] 5 O^(RI) = 1 RI[1] 6 O^(RI) = 2RI[2]

Table 1 illustrates six (6) exemplary control signals with predefinedencoding categories. To simplify forgoing description, six (6) controlsignals are renamed or referred to as ACK [1], ACK[2], ACK[3], ACK[4],RI[1], and RI [2], respectively. For example, 1-bit ACK “O^(AcK)=1” isreferred to as ACK[1] and 1-bit ACK bundling is referred to as ACK [2].2-bit ACK “O^(ACK)=2” is referred to as ACK[3] and 2-bit ACK bundling isreferred to as ACK[3]. Similarly, 1-bit RI “O^(RI)=1” is referred to asRI[1] and 2-bit RI “O^(RI)=2” is referred to as RI [2]. Note that ACK[1] indicates that ACK control signal with one (1) bit to indicate itsvalue and ACK [3] indicates that ACK control signal uses two (2) bits toindicate its value. ACK bundling reduces the number of ACKs to betransferred in TDD-LTE (Time Division Duplexing LTE) networks by alogical AND operation between the ACKs belonging to multiple downlinksubframes.

Descrambler (Block 218)

The descrambler 218 is configured to generate a descrambling sequence ofbits or a stream of bits. For example, after generating a sequence inaccordance with the input value, the descrambler determines whethersequence modification is needed for certain categories of controlinformation. The stream of bits or sequence is subsequently descrambledto produce a set of descrambled soft bits.

Combiner/Extractor (Block 220)

The combiner/extractor 220 provides a combining and extracting functionto combine descrambled soft bits from the descrambler 218 and extractUplink Control Information (“UCI”).

FIG. 4 shows an exemplary method 400 for performing demapping inaccordance with exemplary embodiments of a demapping system. Forexample, the method 400 is suitable for use with the demapping system152 shown in FIG. 2. In various exemplary embodiments, the method 400operates to perform demapping operations for three processing typeswhile reusing the same hardware of the demapping system 152, therebyproviding fast and efficient demapping of received 4G and 5G uplinktransmissions.

At block 402, uplink transmissions are received in a 4G/5G communicationnetwork. For example, the uplink communications are received at thefront end 228 shown in FIG. 2.

At block 404, gain normalization is performed. For example, the gainnormalization is performed by the gain normalizer 202 shown in FIG. 2.

At block 406, an inverse Fourier transform is performed to obtain timedomain signals. For example, this process is performed by the IDFT block204 shown in FIG. 2.

At block 408, a determination is made as to a type of processing to beperformed. For example, a description of three processing types isprovided above. If a first type of processing is to be performed, themethod proceeds to block 410. If a second type of processing is to beperformed, the method proceeds to block 420. If a third type ofprocessing is to be performed, the method proceeds to block 414. Forexample, this operation is performed by the processing type detector 208shown in FIG. 2.

At block 420, when the processing type is Type 2, despreading isperformed on the received resource elements. For example, this operationis performed by the despreader 214 shown in FIG. 2. The method thenproceeds to block 414.

When the processing type is Type 3, the method proceeds to block 414.

When the processing type is Type 1, the follow operations are performed.

At block 410, the reference signals are removed from the receivedresource elements. For example, resource elements containing RS/DTX areremoved. This operation is performed by the RS remover 210 shown in FIG.2.

At block 412, layer demapping is performed. For example, the resourceelements without RS/DTX are layer demapped. This operation is performedby the layer demapper 212.

At block 414, soft demapping is performed. For example, the softdemapper 216 soft-demaps bits for each processing type. Duringprocessing Type 3, the soft demapper 216 receives the resource elementsand soft demaps these bits to produce a soft-demapped output. Duringprocessing Type 2, the soft demapper 216 receives the despread bits fromthe despreader 214 and soft demaps these bits to produce a soft-demappedoutput. During processing Type 1, the soft demapper 216 receives thelayer demapped bits from the layer demapper 212 and soft demaps thesebits to produce a soft-demapped output.

At block 416, descrambling is performed. For example, the descrambler218 receives the soft demapped bits from the soft demapper 216 andgenerates descrambled bits.

At block 418, combining and extraction of UCI information is performed.For example, the combiner/extractor 220 receives the descrambled bits,combines these bits, and extracts the UCI information.

Thus, the method 400 operates to provide demapping in accordance withthe exemplary embodiments. It should be noted that the operations of themethod 400 could be modified, added to, combined, deleted, rearranged,or otherwise changed within the scope of the embodiments.

FIG. 5 shows an exemplary embodiment of the phase compensator 232 foruse in the soft demapper provided in the demapping system shown in FIG.2. In an embodiment, the phase compensator 232 is configured to reducephase noise especially in high frequency wireless communication systemsfor better communication quality. In an embodiment, the phasecompensator 232 comprises multiplier 502, shift and rounding circuits504, 510, saturation circuits 506, 512, and phase coefficient calculator524 that calculates a phase compensation coefficient 508.

During operation, the phase coefficient calculator 524 calculates thephase compensation coefficient 508. In an embodiment, the calculator 524receives as input received reference symbols 526 that are part of thereceived symbols 234 shown in FIG. 2. The calculator 524 also receivesgenerated reference symbols 528 that are internally generated in anothercircuit of the demapping system 152. The calculator 524 determines aphase difference between the received symbols 234 and the generatedsymbols 528 and uses this difference to calculate the phase compensationcoefficient 508 that is a fixed-point complex value represented in Q14format. In an embodiment, the calculator 524 calculates up to four phasecompensation coefficients for up to four layers.

The multiplier 502 receives FQ bits 514 that comprise 16-bit values. Themultiplier 502 also receives the phase compensation coefficient 508 thatalso comprises 16-bits. The multiplier multiples its inputs to generatean output 518 that comprises 33-bits representing real (Re) andimaginary (Im) parts that are input to the shift and rounding circuit504 and the shift and rounding circuit 510, respectively.

The shift and rounding circuit 504 receives the Re bits and right shiftsthis Re input by 14-bits and rounds the result. The output of the shiftand rounding circuit 504 is input to the saturation circuit 506.Likewise, the shift and rounding circuit 510 receives the Im bits andright shifts this Im input by 14-bits and rounds the result. The outputof the shift and rounding circuit 510 is input to the saturation circuit512.

The saturation circuit 506 adjusts a saturation level of the shifted androunded Re bits. For example, the 16-bit saturation circuit 506 adjuststhe saturation level of the shifted and rounded Re bits so as tomaintain Re values within a range of (2¹⁵−1 to −2¹⁵). The saturationadjusted Re bits 520 are then output.

The saturation circuit 512 adjusts a saturation level of the shifted androunded Im bits. For example, the 16-bit saturation circuit 512 adjuststhe saturation level of the shifted and rounded Im bits so as tomaintain Im values within a range of (2¹⁵−1 to -2¹⁵). The saturationadjusted Im bits 520 are then output. The Re bit 520 and Im bits 522represent phase compensated FQ bits that are input to the next stage ofthe soft demapper 216.

FIG. 6 shows an exemplary embodiment of a soft demapper 600 for use inthe demapping system shown in FIG. 2. In an embodiment, the softdemapper 600 is suitable for use as the soft demapper 216 shown in FIG.2. In an embodiment, the soft demapper 600 comprises multipliers 602,612, shift and round (RND) circuits 604, 610, LLR offset circuit 606,and saturation circuit 608.

During operation, the soft demapper 600 receives the phase compensated Iand Q bits 520/522 and multiplies these signals by a scaled SINR signal.For example, an SINR signal 624 is input to multiplier 612. A modulation(MOD) scale signal 626 is also input to the multiplier 612. An output ofthe multiplier 612 is input to the shift and round circuit 610 thatshifts its input right by RSFT1 bits and rounds the result. The outputof the shift and round circuit 610 is input the multiplier 602, whichalso receives the phase compensated I and Q bits 520/522. An output ofthe multiplier 602 is input to the shift and round circuit 604, whichshifts it input right by RSFT2 bits and rounds the result. The output ofthe shift and round circuit 604 is input to the LLR offset circuit 606.An offset signal 620 is used to apply an offset and the resulting outputis input to the saturation circuit 608 which adjusts a saturation levelits input signal to generate the phase compensated soft demapped LLRsignal 622.

FIG. 7 shows an exemplary method for performing I/Q phase compensationfor use with the soft demapper 216 provided in the demapping systemshown in FIG. 2. For example, the method 700 is suitable for use withthe phase compensation circuit 232 shown in FIG. 4.

At block 702, I/Q bits are received at a soft demapper. For example, I/Qbits are received at the soft demapper 216 shown in FIG. 2. The I/Q bitscan be received from any of the blocks 208, 212, or 214, as shown inFIG. 2. In an embodiment, the I/Q bits are received at the phasecompensation circuit 232 of the soft demapper 216.

At block 704, a phase compensation coefficient is determined. Forexample, the phase coefficient calculator 524 calculates thecompensation coefficient 508 by comparing the phase of internallygenerated reference symbols 528 to received reference symbols 526.

At block 706, the received I and Q bits are multiplied by the calculatedcoefficient. For example, the multiplier 502 multiples the FQ bits 514and the phase coefficient 508 to generate real (Re 33-bits) andimaginary (Im 33-bits) values.

At block 708, the Re values are shifted and rounded. For example, the Rebits are input to the shift and round circuit 504 where they are rightshifted by 14-bits and then rounded.

At block 710, the Im values are shifted and rounded. For example, the Imbits are input to the shift and round circuit 510 where they are rightshifted by 14-bits and then rounded.

At block 712, adjustment of a saturation level of the shifted androunded Re bits is performed. For example, the 16-bit saturation circuit506 adjusts the saturation level of the shifted and rounded Re bits soas to maintain Re values within a range of (2¹⁵−1 to −2). The saturationadjusted Re bits 520 are then output.

At block 714, adjustment of a saturation level of the shifted androunded Im bits is performed. For example, the 16-bit saturation circuit512 adjusts the saturation level of the shifted and rounded Im bits soas to maintain Im values within a range of (2¹⁵−1 to −2′). Thesaturation adjusted Im bits 522 are then output.

At block 716, soft demapping is performed on the phase compensated FQbits. For example, the phase compensated FQ bits 520/522 are input tothe soft demapper 600 to generate soft demapped LLR bits 622.

At block 718, the soft demapped LLR bits 622 are input to thedescrambler 218.

Thus, the method 700 operates to provide phase compensated softdemapping in accordance with the exemplary embodiments. It should benoted that the operations of the method 700 could be modified, added to,combined, deleted, rearranged, or otherwise changed within the scope ofthe embodiments.

FIG. 8 is a block diagram illustrating a processing system 800 having anexemplary embodiment of a demapping system 830. It will be apparent tothose of ordinary skill in the art that other alternative computersystem architectures may also be employed.

The system 800 includes a processing unit 801, an interface bus 812, andan input/output (“IO”) unit 820. Processing unit 801 includes aprocessor 802, main memory 804, system bus 811, static memory device806, bus control unit 805, and mass storage memory 808. Bus 811 is usedto transmit information between various components and processor 802 fordata processing. Processor 802 may be any of a wide variety ofgeneral-purpose processors, embedded processors, or microprocessors suchas ARM® embedded processors, Intel® Core™2 Duo, Core™2 Quad, Xeon®,Pentium™ microprocessor, AMD® family processors, MIPS® embeddedprocessors, or Power PC™ microprocessor.

Main memory 804, which may include multiple levels of cache memories,stores frequently used data and instructions. Main memory 804 may be RAM(random access memory), MRAM (magnetic RAM), or flash memory. Staticmemory 806 may be a ROM (read-only memory), which is coupled to bus 811,for storing static information and/or instructions. Bus control unit 805is coupled to buses 811-812 and controls which component, such as mainmemory 804 or processor 802, can use the bus. Mass storage memory 808may be a magnetic disk, solid-state drive (“SSD”), optical disk, harddisk drive, floppy disk, CD-ROM, and/or flash memories for storing largeamounts of data.

I/0 unit 820, in one example, includes a display 821, keyboard 822,cursor control device 823, decoder 824, and communication device 825.Display device 821 may be a liquid crystal device, flat panel monitor,cathode ray tube (“CRT”), touch-screen display, or other suitabledisplay device. Display 821 projects or displays graphical images orwindows. Keyboard 822 can be a conventional alphanumeric input devicefor communicating information between computer system 800 and computeroperators. Another type of user input device is cursor control device823, such as a mouse, touch mouse, trackball, or other type of cursorfor communicating information between system 800 and users.

Communication device 825 is coupled to bus 812 for accessing informationfrom remote computers or servers through wide-area network.Communication device 825 may include a modem, a router, or a networkinterface device, or other similar devices that facilitate communicationbetween computer 800 and the network. In one aspect, communicationdevice 825 is configured to perform wireless functions. Alternatively,demapping system 830 and communication device 825 perform the demappingfunctions in accordance with one embodiment of the present invention.

The demapping system 830, in one aspect, is coupled to bus 811 and isconfigured to demap received uplink communications as described above toimprove overall receiver performance. The demapping system 830 compriseshardware, firmware, or a combination of hardware and firmware.

While particular embodiments of the present invention have been shownand described, it will be obvious to those skilled in the art that,based upon the teachings herein, changes and modifications may be madewithout departing from this exemplary embodiments of the presentinvention and its broader aspects. Therefore, the appended claims areintended to encompass within their scope all such changes andmodifications as are within the true spirit and scope of this exemplaryembodiments of the present invention.

What is claimed is:
 1. A method, comprising: detecting a processing type associated with a received uplink transmission; and when the detected processing type is a first processing type then performing operations of: removing resource elements containing reference signals from the uplink transmission; layer demapping remaining resource elements of the uplink transmission into two or more layers; phase compensating all layers to generate phase compensated layers; and soft-demapping all phase compensated layers to produce phase compensated soft-demapped bits.
 2. The method of claim 1, wherein when the detected processing type is a second processing type then performing operations of: despreading the received uplink transmission to produce despread I and Q bits; phase compensating the despread I and Q bits; and soft-demapping the phase compensated despread I and Q bits to produce phase compensated soft-demapped bits.
 3. The method of claim 1, wherein when the detected processing type is a third processing type then performing operations of: performing an inverse discrete Fourier transform (IDFT) on the received uplink transmission to generate an IDFT output having I and Q bits; phase compensating the I and Q bits to generate phase compensated I and Q bits; and soft-demapping the phase compensated I and Q bits to produce phase compensated soft-demapped bits.
 4. The method of claim 1, wherein the operation of removing the resource elements comprises removing the resource elements containing phase tracking reference signals (“PTRS”).
 5. The method of claim 1, wherein the operation of removing the resource elements comprises removing the resource elements containing demodulation reference signals (“DMRS”).
 6. The method of claim 1, wherein the operation of removing the resource elements comprises removing the resource elements indicating discontinuous transmissions (“DTX”).
 7. The method of claim 1, wherein the operation of phase compensating comprises: calculating a phase compensation coefficient; multiplying I and Q bits by the phase compensation coefficient to generate real (Re) and imaginary (Im) bit values; shifting and rounding the Re and Im bit values to generated shifted Re and Im bit values, respectively; and adjusting saturation levels of the shifted Re and Im bit values to generate phase compensated I and Q bit values.
 8. The method of claim 1, further comprising receiving the uplink transmission from user equipment in one of a fourth generation (4G) or fifth generation (5G) wireless network.
 9. The method of claim 1, wherein the operation of detecting comprising detecting that the processing type is the first processing type when the received uplink transmission is received from a wireless network configured for fifth generation (5G) new radio (NR) PUCCH format
 4. 10. The method of claim 2, wherein the operation of detecting comprising detecting that the processing type is the second processing type when the received uplink transmission is received from a wireless network configured for one of 5G NR DFT-s-OFDM or 5G NR CP-OFDM.
 11. The method of claim 3, wherein the operation of detecting comprising detecting that the processing type is the third processing type when the received uplink transmission is received from a wireless network configured for one of 4G LTE DFT-s-OFDM or 4G LTE sub-PRB allocation.
 12. An apparatus, comprising: a detector that detects a processing type associated with a received uplink transmission; a reference signal (RS) remover that removes resource elements containing reference signals from the uplink transmission, when the detected processing type is a first processing type; a layer demapper that demaps remaining resource elements of the uplink transmission into two or more layers, when the detected processing type is the first processing type; a phase compensation circuit that phase compensates all layers; and a soft demapper that soft-demaps two or more phase compensated layers to produce phase compensated soft-demapped bits, when the detected processing type is the first processing type.
 13. The apparatus of claim 12, further comprising: a despreader that despreads the received uplink transmission to produce despread I and Q bits when the detected processing type is a second processing type; and wherein the phase compensation circuit phase compensates the despread I and Q bits and the soft demapper soft-demaps the phase compensated despread I and Q bits to produce phase compensated soft-demapped bits.
 14. The apparatus of claim 12, further comprising: an inverse Fourier transform circuit that performs an inverse Fourier transform (IDFT) on the received uplink transmission to generate an IDFT output having I and Q bits when the detected processing type is a third processing type; and wherein the phase compensation circuit phase compensates the I and Q bits and the soft demapper soft-demaps the phase compensated I and Q bits to produce phase compensated soft-demapped bits.
 15. The apparatus of claim 12, wherein the phase compensation circuit performs operations of: calculating a phase compensation coefficient; multiplying I and Q bits by the phase compensation coefficient to generate real (Re) and imaginary (Im) bit values; shifting and rounding the Re and Im bit values to generated shifted Re and Im bit values, respectively; and adjusting saturation levels of the shifted Re and Im bit values to generate phase compensated I and Q bit values.
 16. The apparatus of claim 12, further comprising a front end that receives the uplink transmission from user equipment in one of a fourth generation (4G) or fifth generation (5G) wireless network.
 17. The apparatus of claim 12, wherein the detector detects that the processing type is the first processing type when the received uplink transmission is received from a wireless network configured for fifth generation (5G) new radio (NR) PUCCH format
 4. 18. The apparatus of claim 12, wherein the detector detects that the processing type is the second processing type when the received uplink transmission is received from a wireless network configured for one of 5G NR DFT-s-OFDM or 5G NR CP-OFDM.
 19. The apparatus of claim 12, wherein the detector detects that the processing type is the third processing type when the received uplink transmission is received from a wireless network configured for one of 4G LTE DFT-s-OFDM or 4G LTE sub-PRB allocation.
 20. An apparatus, comprising: means for detecting a processing type associated with a received uplink transmission; and means for performing phase compensated soft-demapping that performs operations of: determining when the detected processing type is a first processing type and performing operations of: removing resource elements containing reference signals from the uplink transmission; layer demapping remaining resource elements of the uplink transmission into two or more layers; phase compensating all layers; and soft-demapping all layers to produce phase compensated soft-demapped bits; determining when the detected processing type is a second processing type and performing operations of: despreading the received uplink transmission to produce despread I and Q bits; phase compensating the despread I and Q bits; and soft-demapping the phase compensated despread I and Q bits to produce phase compensated soft-demapped bits; and determining when means the detected processing type is a third processing type and performing operations of: performing an inverse discrete Fourier transform (IDFT) on the received uplink transmission to generate an IDFT output having I and Q bits; phase compensating the I and Q bits to generate phase compensated I and Q bits; and soft-demapping the phase compensated I and Q bits to produce phase compensated soft-demapped bits. 